In 2015, Tankwell (based in Wieringerwerf, Netherlands) introduced a novel technology for manufacturing high quality composite tank containers. “The entire tank is made in one filament winding step, instead of the traditional method of combining separate end-caps onto a circular filament wound core. This means the wall thickness of the composite tank is lower than for comparable composite tank structures,” explains Casper Willems, Managing Director of Tankwell. “For our tank containers an external frame is incorporated in the overall design, resulting in an assembly with excellent rigidity and mechanical integrity.The manholes, valves and auxiliary components are still standard parts in metal and are nicely integrated in the composite structure.”
For this application, Tankwell is using the Atlac 5200 FC resin from Aliancys (delivered by Distributor Euroresins). This high strength vinyl ester resin can resist a broad range of chemicals, which it say makes the tank container suitable for a variety of end uses. The Atlac 5200 FC resin is produced according to Good Manufacturing Practice (GMP), a common standard used for making food contact products. “Aliancys has been supporting Tankwell in resin selection, and in the fine-tuning of design and processing,” adds Rob van de Laarschot, Head of Technical Service at Aliancys.
“In order to understand the fit of using the tanks for specific chemicals, we can build on our Chemical Resistance information system with years of chemical resistance testing on our resins.”
According to Aliancys, the result is very impressive: the composite swap body tank container with a capacity of 31,000 liters only weighs as little as 2,200 kg, which is 40% less than the traditional stainless steel tank containers. Jacco van Holten, Commercial Director at Den Hartogh Logistics, states, “These newly designed tank containers will transport 2 metric tons of product more on every trip. Freight cost is dropping by 5 to 10% as a direct result. Together with this significant increase on payload, comes the saving on actual loading and unloading operations. More payload simply means less transport movements, less CO2 emission, less physical handlings, less congestion, less risk.”
The newly constructed composite tank containers are said to have a 40% better thermal insulation compared to stainless steel tank containers. Jacco van Holten adds, “The need for re-heating of the product, prior to the customer delivery, is eliminated with these composite tank containers. This results directly in huge savings on heating costs, but also here a significant indirect effect on improved safety performance and on time delivery at the final customer is to be expected.”
An additional benefit of using composite tank containers, as experienced by Den Hartogh, is the relative smoothness of the inner surface. Aliancys says that, while stainless steel surfaces may suffer from pitting and can retain traces of a product from a previous load, the composite surfaces remain cleaner and require less intensive scrubbing. The result is reduced cost, a reduction of the quantity of chemicals that need to be disposed after cleaning, and less empty kilometers caused by restrictions linked to previous cargo.
The composite tank container has obtained ADR, RID, CSC and IMO4 approval after extensive material and product testing under third party surveillance. The type approval included all relevant fire safety and mechanical impact testing. Since December 2015, Den Hartogh Logistics has been using the composite tank containers in its fleet, which already consists of more than 19,000 tank containers worldwide. The company is gradually increasing the range of chemicals for which the composite tank containers are deployed, with the intention to maximise the benefits this innovative technology can bring.